Assessing the effects of piperonyl butoxide (PBO) exposure on malaria vector fitness (360G-Wellcome-208300_Z_17_Z)

Malaria occurrence has decreased remarkably across sub-Saharan Africa over the past 15 years. This is largely due to the mass distribution of LLINs. However, the main type of malaria vectors, including Anopheles gambiae and Anopheles funestus, have gained resistance to pyrethroids.This threatens the future effectiveness of LLINs, and alternative solutions and compounds are urgently needed. One solution is a long-lasting insecticidal treated net (LLIN) containing both a pyrethroid and a compound known as piperonyl butoxide (PBO). PBO is a synergist that inhibits a group of enzymes (P450s) inside the insect which metabolise pyrethroids causing resistance.P450 enzymes play a large role in other physiological processes in insects such as maintaining hormonal balance and synthesis of the external cuticle. By inhibiting P450s, exposure to PBO may negatively affect these processes causing further reductions in the Anopheles population. This project will look at the impact of exposing local vector populations in southern Malawi to PBO-LLINs and quantifying the impact of exposure on mosquito longevity and reproduction. Exposure to PBO-LLINs will also determine whether PBO modifies these mechanisms and make mosquitoes more susceptible to pyrethroids. This project will help inform policy makers of the effectiveness of PBO-LLINs as part of vector control strategies.